JP2990039B2 - Method for producing azo pigment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing azo pigments, and more particularly to paints, printing inks, plastics,
The present invention relates to a method for producing an azo pigment suitable for uses such as stationery.

[0002]

2. Description of the Related Art Benzimidazolone-based azo pigments are particularly excellent among azo pigments and can be used as substitutes for high-grade polycyclic pigments in applications such as paints and gravure inks requiring weather resistance and solvent resistance. Can be used as

[0003] However, these pigments are obtained in the form of hard particles having fine particles and low crystallinity almost immediately after coupling. If the aqueous suspension of the crude pigment after coupling is heated to a temperature of 80 to 150 ° C. for several hours as is usually performed, the particles of the crude pigment do not grow sufficiently in crystals, and the resulting pigment Hue becomes turbid,
This is an unsuitable form for practical use due to lack of dispersibility, light resistance, concealing property and the like.

[0004] When the above-mentioned pigment is used especially for paints, it cannot be used in such applications because the binder absorbability of the pigment is too high and the fluidity of the paint is low. Therefore, these pigments require some post-treatment to obtain the optimal pigment morphology.

[0005]

As a method for solving such a problem, for example, a method of treating a crude pigment at a high temperature in a polar organic solvent (Japanese Patent Publication No. 38-16048) is known. . However, in this method,
The crystal elongation is not enough, the particle shape of the obtained pigment is hard, and there is a fear of poor dispersion, and the organic solvent used is generally removed by steam distillation after the treatment. Is difficult to completely remove from the pigment, and there is a concern that the poorly volatile solvent remains in the pigment and the quality of the pigment deteriorates. For this reason, it is necessary to pulverize and wash the press cake obtained by filtration with a washing solvent such as methanol, or a method that can be economically satisfied in terms of recovery facilities and yield of these organic solvents. is not.

Also, for example, a method in which a crude pigment is heated to a temperature of 80 to 150 ° C. in an aqueous suspension composed of a mixture of water and an organic solvent which is completely or only partially miscible with water. (JP-A-49-116131),
There are the problems of residual solvent and the disadvantage that a special pressurizing device for performing heat treatment under high pressure is required.

Further, for example, the crystals of the α-modified pigment particles obtained by coupling are converted into a β-modified crystal structure by heat treatment, separated, and the crude pigment is suspended in water. Heating at 130 to 160 ° C. (Japanese Patent Publication No. 64-5624), or heating a specific azo pigment in a neutral or acidic aqueous suspension containing benzoic acid or benzoic acid and an inorganic salt, for example. In the treatment method (JP-A-56-67370), depending on the structure of the pigment, the crystals do not grow to the target particle form unless the pressure is considerably increased during the heat treatment, and the hue of the obtained pigment is unclear and The viscosity when dispersed in a lacquer is so high that a pigment which can be practically used in paints cannot be obtained.

Further, in an organic solvent, the obtained pigment has a hard particle morphology, which may cause poor dispersion, and may cause problems such as washing with methanol or the like in order to remove the solvent used for crystallization. In each of these methods, the crude pigment is used in the form of an aqueous paste or a dry substance. For this reason, the crude pigment after coupling must be once filtered. Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide an azo pigment suitable for use in paints, printing inks, plastics, stationery and the like.

[0009]

The above object is achieved by the present invention described below. That is, the present invention provides a method for heating a crude azo pigment together with an aromatic compound having a water-soluble group at a temperature of 80 ° C. or higher for a sufficient time to convert the crystal of the crude pigment into a pigment form. A method for producing an azo pigment in which an aromatic compound having
The crude azo pigment has a benzimidazolone group in the structure.
In the case of an acetoacetic anilide-based azo pigment to be
An acidic or neutral aqueous suspension of
Naphthol azo having a benzimidazolone group during production
In the case of pigments, a neutral aqueous suspension of the pigment is
In the process of raising the temperature to the above temperature, the pigment in the aqueous phase becomes water-soluble
Transfer to the aromatic compound phase with chromium groups to form magma
And then subjecting the magma to a heat treatment at the above temperature by further raising the temperature .

[0010] The present invention also relates to an aqueous suspension of a crude azo pigment.
80 ° C. together with an aromatic compound having a water-soluble group as a liquid
Heat treatment is performed at the above temperature for a sufficient time to set the crude pigment.
After converting the crystal into a pigment form, it has the above water-soluble group
Aromatic compounds are dissolved in water by alkaline aqueous solution
For producing an azo pigment for separating the pigment form product
In the method, the crude azo pigment contains benzimidazolo in the structure.
Acetoacetate anilide-based and naphthol-based
And an alkaline aqueous suspension of the pigment.
Method for producing azo pigments characterized by heat treatment at a temperature
Is the law.

Further, the present invention relates to an aqueous suspension of a crude azo pigment.
80 ° C. together with an aromatic compound having a water-soluble group as a liquid
Heat treatment is performed at the above temperature for a sufficient time to set the crude pigment.
After converting the crystal into a pigment form, it has the above water-soluble group
Aromatic compounds are dissolved in water by alkaline aqueous solution
For producing an azo pigment for separating the pigment form product
In the method, the crude azo pigment contains benzimidazolo in the structure.
Naphthol-based azo pigments having
The aqueous suspension is heated under pressure at a temperature of 100 ° C or higher.
This is a method for producing an azo pigment.

[0012]

According to the present invention, crude azo pigments are added together with hydroxynaphthalene or a derivative thereof, generally under normal pressure for 8 hours.
By performing the heat treatment at a temperature of 0 ° C. or higher, the crystals can be grown from the crude pigment to a form suitable for use in paints and gravure inks.

That is, by heating the crude azo pigment obtained by the coupling together with hydroxynaphthalene or a derivative thereof, it can be converted to a pigment form suitable for a paint or gravure ink. For this purpose, it is important to use hydroxynaphthalene or a derivative thereof as a crystallization agent for the crude azo pigment, and by heating an aqueous suspension of the crude pigment with hydroxynaphthalene or a derivative thereof, the pigment is removed from the aqueous phase. The organic phase (hydroxynaphthalene or its derivative),
By holding at a temperature of 80 ° C. or higher for several hours, a pigment in a crystalline form most suitable for applications such as paints, printing inks, and plastics can be obtained.

After the heat treatment, hydroxynaphthalene or a derivative thereof is dissolved in water by adding an alkali agent, for example, an aqueous alkali solution such as an aqueous caustic soda solution, at a temperature not so high, and the pigment-form product is separated by filtration. I do. After the pigment is separated, the alkali filtrate can be neutralized with a mineral acid to precipitate and regenerate hydroxynaphthalene or a derivative thereof, recovered, and reused.

Further, in the present invention, as described in the above-mentioned patent publication, if the crude pigment is subjected to a heat treatment under pressure, the crystal of the pigment particles is much easier to grow than the previous method. In addition, the amount of hydroxynaphthalene or its derivative used can be greatly reduced in order to obtain a pigment having a desired crystal form. In some cases, when heating the aqueous suspension of the crude pigment together with hydroxynaphthalene or a derivative thereof, a method in which an alkaline agent is added first and the slurry is treated in a slurry state is also possible.

The present invention can be applied to the treatment of all crude azo pigments. Particularly preferred pigments are acetoacetic anilide azo pigments having a benzimidazolone structure or naphthol azo pigments. Are obtained by using 5-aminobenzimidazolone as a diazo component and coupling with an existing acetoacetic anilide used for an ordinary azo pigment, and 5-
The one obtained by coupling with the existing diazo component used for ordinary azo pigments using acetoacetylaminobenzimidazolone, and the one used for ordinary azo pigments using 5-aminobenzimidazolone as the diazo component Obtained by coupling with a naphthol AS, and an existing diazo component used in a common azo pigment using 5- (2 ', 3'-oxynaphthoylamino) benzimidazolone as a coupling component For the purpose of improving the suitability for use of these pigments and those obtained by ringing, a mixture of these pigments with a sulfonated product or a carboxylated product of these pigments may, for example, be mentioned. Furthermore, the method of the present invention is also effective for known dianthraquinonyl pigments, substituted quinacridone pigments, and quinacridone solid solution pigments.

Preferred specific examples of hydroxynaphthalene or a derivative thereof used as a crystallization agent for the crude pigment in the present invention include α-naphthol and β-naphthol, as well as α-naphthol and β-naphthol halides and sulfones. And β-naphthol is economically advantageous to use.

According to the present invention, in order to use hydroxynaphthalene or a derivative thereof instead of an organic solvent as a crystallization agent for pigment particles, a special apparatus or equipment such as a distillation facility is used for recovery of the crystallization agent. It is not necessary, and the recovery of the crystallization agent is remarkably easy as compared with the organic solvent. When an organic solvent is used as a crystallization agent, the solvent is generally removed from the treated pigment by steam distillation, but it is difficult to completely remove the organic solvent from the pigment, and a cleaning solvent such as methanol is used. In some cases, the volatile solvent in the pigment must be removed. Further, in the present invention, since the heat treatment is generally performed under normal pressure, no special device or equipment such as a pressurizing facility is required, and the treatment in a normal coupling tank is also possible. For this reason, the processing operation is simplified and no special equipment is required, so that a pigment having a form suitable for a paint or gravure ink can be produced at low cost.

The method of the present invention is to directly or crudely prepare a crude azo pigment obtained by coupling, particularly in a coupling slurry of an acetoacetic anilide azo pigment or a naphthol azo pigment having a benzimidazolone structure. After filtration, hydroxynaphthalene or its derivative in an amount of 10 to 300% by weight based on the azo pigment is added to a slurry obtained by peptizing the press cake again in water. The temperature is raised to a temperature of at least 100 ° C., preferably 85 ° C. to 100 ° C., and further maintained at this temperature for several hours until the desired pigment form is obtained. In the case of a naphthol-based azo pigment having a benzimidazolone structure, it is particularly preferable to perform the treatment under pressure at a temperature of 100 ° C. or higher and in a neutral atmosphere.

After the pigment suspension after the treatment is cooled to a temperature of 90 to 70 ° C., an alkali agent, for example, a 10% by weight aqueous solution of caustic soda is added to dissolve hydroxynaphthalene or a derivative thereof in alkaline water. The pigmented product is separated by filtration and the separated product is washed with warm or cold water until neutral. The obtained pigment form product is dried and pulverized by a usual method, and used for applications such as paints, printing inks and plastics. Further, the transparency of the pigment is adjusted depending on the aging condition of the pigment after the treatment, so that the pigment can be used for applications requiring transparency, such as color filters and electrophotographic toners.

Further, from the alkaline filtrate from which the pigment-form product has been separated after the treatment, hydroxynaphthalene or a derivative thereof can be easily recovered by neutralization with an acid. If the recovered hydroxynaphthalene or its derivative is strongly colored, it can be decolorized using activated carbon and reused.

The pigment thus obtained has a clear hue and is finished in a very soft particle form. Therefore, when used for coloring paints, printing inks, plastics, and the like,
It shows surprisingly good dispersibility. In addition, even when the transparency is adjusted by the aging conditions after the treatment, and the transparency is required for applications such as color filters and toners for electrophotography, the particles can be obtained in a soft particle form. Shows sex.

[0023]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following description, parts and% are parts by weight and% by weight, respectively, unless otherwise specified. Example of acetoacetic anilide-based pigment Example 1 34.5 parts of 2-nitro-4-chloroaniline was added to 200
The mixture was dispersed in a 4N aqueous hydrochloric acid solution at room temperature for 3 hours or more, and then cooled to 0 ° C. Then add 48.3 parts of 3
After diazotization by adding a 0% aqueous nitrous acid solution, excess nitrous acid was decomposed with sulfamic acid, diatomaceous earth was added, and insolubles were removed by filtration to obtain a clear pale yellow diazonium salt solution.

At the same time, 46.6 parts of 5-acetoacetylaminobenzimidazolone are dissolved in 305 parts of a 2N aqueous solution of caustic soda, cooled and precipitated with 320 parts of a 2N aqueous solution of acetic acid, and the temperature is adjusted to 20 ° C. . The diazonium salt solution is added dropwise to the coupler suspension at 20 ° C. over 80 minutes, and the mixture is stirred for 2 hours or more to complete the coupling reaction. The black-brown suspension obtained by this coupling reaction was heated to 90 ° C.
Aging at -95 ° C for 2 hours gives a crude orange-brown brown pigment. Water is added to this crude pigment suspension and
After cooling to 430 parts, suction filtration and washing with water were performed to obtain 430 parts of a wet pigment cake (19.4% dry matter).

After dispersing 103 parts of the above wet cake in 150 parts of water, 40 parts of β-naphthol is added and heated with stirring. As the temperature increases, the brown slurry begins to give an orange tint, and a "flash" occurs at 80-90 [deg.] C., where the crude pigment initially suspended in water migrates into the molten [beta] -naphthol and becomes small-granular. To form large orange-brown magmas. The mixture was further stirred at 95 ° C. for 5 hours and then cooled to 85 ° C.
150 parts of a 2N aqueous solution of caustic soda were added to add β
-Dissolve naphthol in water.

The resulting orange pigment suspension is filtered with suction,
After washing to neutrality with water and drying, 19.6 parts of a very bright and soft orange pigment are obtained. Further, the alkali mother liquor and the first washing liquid after the pigment was separated were acidified with hydrochloric acid after cooling, and 37.5 by precipitation and filtration.
Some of the β-naphthol was recovered.

Example 2 17.3 parts of 2-nitro-4-chloroaniline were added to 100 parts
The mixture was dispersed in a 4N aqueous hydrochloric acid solution at room temperature for 3 hours or more, and then cooled to 0 ° C. Next, 24.2 parts of a 30% nitrous acid aqueous solution was added to diazotize the mixture, and insoluble materials were removed with diatomaceous earth in the same manner as in Example 1. Further, excess nitrous acid was decomposed with sulfamic acid, and the solution was clarified. A pale yellow diazonium salt solution was obtained.

At the same time, 23.3 parts of 5-acetoacetylaminobenzimidazolone are dissolved in 153 parts of a 2N aqueous sodium hydroxide solution, and then precipitated with 160 parts of a 2N aqueous acetic acid solution, and the temperature is adjusted to 20 ° C. After the above-mentioned diazonium salt solution is added dropwise to this coupler suspension at 20 ° C. over 60 minutes, the mixture is stirred for 2 hours or more to complete the coupling reaction. The black-brown suspension obtained by this coupling reaction was heated to 90 ° C, and further heated to 90 to 95 ° C.
For 2 hours to obtain an orange-brown crude brown pigment.

After the crude pigment suspension was cooled to 70 ° C., 42 parts of β-naphthol were added, and 1 part of the suspension was stirred.
When 6.5 parts of caustic soda were added and the temperature was raised to 90 ° C., the slurry remained suspended and turned brownish orange. When the suspension is kept at 90 to 95 ° C. and stirring is continued, the slurry gradually loses its brown color and gradually changes to a reddish orange color. After maintaining this state for 5 hours, the mixture was cooled to 80 ° C., and 39.3 parts of a very bright and soft reddish orange pigment was obtained by suction filtration and washing.
The alkali mother liquor after the pigment had been separated and the first wash were cooled and acidified with hydrochloric acid to recover 40.3 parts of β-naphthol.

Example 3 85 parts of β-naphthol was added to a coupling suspension of a crude black-brown pigment obtained in the same manner as in Example 1, and
Heat with stirring. As the temperature increases, the black-brown slurry begins to brown gradually and at 80-90 ° C. the suspension becomes small brown particles and then aggregates to form large brown magmas. The mixture was further stirred at 95 ° C. for 8 hours, cooled to 85 ° C., and an aqueous solution containing 25 parts of caustic soda was added to dissolve β-naphthol, whereby an orange pigment suspension was obtained.

The obtained pigment suspension was filtered by suction, washed with water until neutral, and dried to obtain 79.2 parts of a bright and soft orange pigment. After cooling, 81.5 parts of β-naphthol were recovered from the alkali mother liquor and the first washing with water after cooling by acidification with hydrochloric acid.

Comparative Example 1 Next, for comparison with the pigment of the present invention, 106 parts (20 g of dry matter) of the crude pigment obtained in the same manner as in Example 1 were subjected to the same method as in Example 1. After dispersing in 150 parts of water, 40 parts of o-nitrophenol was added, heated with stirring, and aged at 90 to 95 ° C. for 10 hours. After cooling to 85 ° C., 155 parts of a 2N aqueous sodium hydroxide solution was added to dissolve o-nitrophenol, followed by filtration and washing with warm water to obtain 19.8 parts of an orange pigment.

Comparative Example 2 In the same manner as in Comparative Example 1, aging was performed at 90 to 95 ° C. for 10 hours using 40 parts of benzoic acid instead of o-nitrophenol. After cooling to 85 ° C., 160 parts of a 2N aqueous sodium hydroxide solution was added to dissolve benzoic acid, followed by filtration and washing with warm water to obtain 19.6 parts of an orange pigment.

Comparative Example 3 In the same manner as in Comparative Example 1, 90 parts of m-nitrobenzenesulfonic acid were used in place of o-nitrophenol, and
Aging was performed at 95 ° C. for 10 hours. After cooling to 85 ° C,
25 parts of a 2N aqueous sodium hydroxide solution was added to dissolve m-nitrobenzenesulfonic acid, followed by filtration and washing with warm water to give 1 part.
9.8 parts of an orange pigment were obtained.

Comparative Example 4 For comparison with the pigment of the present invention, JP-B-3-69
According to the method of Example 1 of JP-A-382, an orange pigment equivalent to the pigment of Example 1 of the present invention was obtained.

Comparative Example 5 For further comparison with the pigment of the present invention, a commercially available pigment Nova Palm Orange HL-70 (manufactured by Hoechst, equivalent to the pigment of Example 1 of the present invention, trademark) was used. .

Comparative Example 6 The azo pigments obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.). The pigment was enamelled with a melamine alkyd paint together with the pigment, and the dispersion particle size, viscosity, color tone, hiding power and weather resistance were measured by the following methods, and the results shown in Table 1 below were obtained.

(1) Method of preparing enamel Pigment: varnish: solvent was mixed in a ratio of 10: 170: 20 and dispersed in a ball mill for 12 hours to prepare a dark enamel. (2) Dispersion Particle Size Dark enamel was measured with a grind gauge. The judgment was made in five stages (1 = poor → 5 = excellent).

(3) Viscosity Using a rotational viscometer, at a temperature of 20 ° C. and a rotational speed of 12 rpm. p. m. Was measured. (4) Color tone Dark enamel, azo pigment: titanium white 1:20
After diluting with white enamel and spreading on art paper using an applicator (6 mil), baking at 140 ° C. for 30 minutes, using a photoelectric colorimeter (manufactured by Suga Test Instruments Co., Ltd.) The respective a and b values were measured.

(5) Hiding power The dark enamel was spread on a hiding power test paper (manufactured by Nippon Test Panel Kogyo Co., Ltd.) using an applicator (6 mil) and baked at 140 ° C. for 30 minutes. It was judged with the naked eye. Judgment is 5 steps 1 = Poor → 5 = Excellent)

(6) Weather resistance A light-colored enamel prepared in the same manner as in the color tone test of (4) is adjusted to a viscosity suitable for spray coating with a solvent, and is applied and baked on a tin plate to obtain a colored coated plate. Was. This colored coated plate is sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.)
For 500 hours, and the color difference ΔE from the unexposed coated plate was measured.

Table 1 (Melamine alkyd baking paint test)

Example 4 32.2 parts of o-aminobenzotrifluoride were added to 20 parts
0 parts of a 3N hydrochloric acid aqueous solution and add ice
Add 0 parts and cool to below 0 ° C. Then 5
After diazotization by adding 0.6 parts of a 30% aqueous solution of nitrous acid, excess nitrous acid is decomposed with sulfamic acid, diatomaceous earth is added, and insolubles are removed by filtration, and a clear pale yellow diazonium salt solution is added. I got

At the same time, 46.6 parts of 5-acetoacetylaminobenzimidazolone are dissolved in 250 parts of a 2N aqueous solution of caustic soda, cooled and precipitated with 260 parts of a 2N aqueous solution of acetic acid, and the temperature is adjusted to 20 ° C. . After the above-mentioned diazonium salt solution is dropped into this coupler suspension at 20 ° C. over 1 hour, the mixture is stirred for 2 hours or more to complete the coupling reaction, whereby a greenish yellow pigment suspension is obtained.

To the obtained pigment suspension are added 40 parts of β-naphthol and 31.5 parts of caustic soda, and the mixture is heated with stirring. When the temperature rises to 90 ° C,
After aging at 5 ° C. for 5 hours, the mixture was cooled to 85 ° C., filtered by suction, washed with water until neutral, and dried to obtain 78.6 parts of a very vivid and soft greenish yellow pigment. Obtained.
38. Alternatively, the alkali mother liquor and the first washing liquid after separating the pigment are cooled and acidified with hydrochloric acid.
Three parts of β-naphthol were recovered.

Example 5 21.3 parts of 1-amino-3,5-di (carboxylic acid methyl ester) benzene was added to 60 parts of a 5N hydrochloric acid aqueous solution, and dispersed at room temperature for 3 hours or more. Then, cool to 0 ° C or lower. Then add 30% of 23 parts
An aqueous nitrous acid solution is added to cause diazotization, diatomaceous earth is added, and insolubles are filtered. Then, excess nitrous acid is decomposed with sulfamic acid.

At the same time, 23.3 parts of 5-acetoacetylaminobenzimidazolone were dissolved in 150 parts of a 2N aqueous solution of sodium hydroxide, cooled, precipitated with 160 parts of a 2N aqueous solution of acetic acid, and then 24.6 parts. Of sodium acetate is added to adjust the temperature to 20 ° C. After the above-mentioned diazonium salt solution is added dropwise to this coupler suspension at 20 ° C. over 1 hour, the mixture is stirred for 1 hour or more to complete the coupling reaction. The suspension obtained by this coupling reaction is heated to 90 ° C. and further aged at 90 to 95 ° C. for 2 hours to obtain a greenish yellow crude pigment. After water was added to the crude pigment suspension and the mixture was cooled to 70 ° C., suction filtration and water washing were performed to obtain 240 parts of a crude pigment wet cake (19.0% dry matter).

After dispersing 105 parts of the above wet cake in 150 parts of water, 41 parts of β-naphthol is added and heated with stirring. When the temperature reaches 80-90 ° C., a “flash” occurs in the water, and the crude pigment initially suspended in the water migrates into the molten β-naphthol to form a magma. The mixture is further stirred at 95 ° C for 5 hours and then cooled to 85 ° C, and β-naphthol is dissolved by adding 150 parts of a 2N aqueous sodium hydroxide solution.

The resulting yellow pigment suspension was filtered by suction,
After washing with water until neutral, it was dried to obtain 19.4 parts of a very bright and soft yellow pigment. Also, the alkali mother liquor and the first washing liquid after separating the pigment are cooled,
By acidification with hydrochloric acid, 38.3 parts of β-
Naphthol was recovered.

Example 6 12.0 parts of anthranilic acid were added to 85 parts of a 3N hydrochloric acid aqueous solution, and the volume was further adjusted to 200 parts by volume with ice, and cooled to 0 ° C. or lower. Next, 23.3 parts of a 30% nitrous acid aqueous solution is added thereto for diazotization, and then diatomaceous earth is added, and insolubles are filtered. After further adding ice, excess nitrous acid was decomposed with sulfamic acid to obtain a clear pale yellow diazonium salt solution.

Simultaneously, 21.5 parts of 5-acetoacetylaminobenzimidazolone are dissolved in 80 parts of a 2N aqueous solution of caustic soda, and the volume is made up to 450 parts by volume with water. This was cooled and precipitated with 31.5 parts of a 30% aqueous acetic acid solution,
Adjust temperature to 20 ° C. After the above diazonium salt solution is added dropwise to this coupler suspension at 20 ° C. over 1 hour, and the mixture is stirred for 2 hours or more to complete the coupling reaction, a greenish yellow pigment suspension is obtained.

15 parts of β-naphthol are added to the obtained pigment suspension and heated with stirring. Temperature 80-90
At "C" a "flash" occurs in the water, with the crude pigment initially suspended in the water forming magma with β-naphthol. The mixture was further stirred at 90 ° C. for 3 hours and then stirred at 85 ° C.
Cool to ℃ and add 75 parts of 2N aqueous sodium hydroxide solution to dissolve β-naphthol.

The resulting greenish-yellow pigment suspension was filtered by suction, washed with water until neutral, and then dried to obtain 34.9 parts of a very bright and soft greenish-yellow pigment. Was.
13. The alkali mother liquor and the first washing liquid after the pigment is separated are cooled and acidified with hydrochloric acid.
Three parts of β-naphthol were recovered.

Example 7 24.4 parts of 1,2-bis- (2-aminophenoxy)
-Ethane is added to 120 parts of a 5N aqueous hydrochloric acid solution, dispersed at room temperature for 3 hours or more, and then cooled to 0 ° C or less with ice.
Next, 47.5 parts of a 30% nitrous acid aqueous solution is added to diazotize the resultant, diatomaceous earth is added, and insolubles are filtered. Then, excess nitrous acid is decomposed with sulfamic acid. At the same time, 46.6 parts of 5-acetoacetylaminobenzimidazolone are dissolved in 250 parts of a 2N aqueous solution of caustic soda, and water is added to make the liquid volume 800 parts by volume. Cool down 280
After precipitation with 2 parts of a 2N acetic acid aqueous solution, a further 41 parts of sodium acetate are added and the temperature is adjusted to 10 ° C.

After the above-mentioned diazonium salt solution is added dropwise to this coupler suspension at 10 to 15 ° C. over 2 hours, the mixture is stirred for 3 hours or more to complete the coupling reaction.
Further, the temperature of the yellow suspension obtained by the coupling reaction is raised to 90 ° C., and the mixture is aged at 90 to 95 ° C. for 1 hour to obtain a crude yellow pigment. After water was added to the crude pigment suspension and the mixture was cooled to 70 ° C., suction filtration and washing with water were carried out to obtain 353 parts of a crude pigment wet cake (dry matter: 20.
3%).

98.5 parts of the above wet cake was added to 150 parts.
After dispersing in water, 40 parts of β-naphthol are added, and if necessary, a necessary amount of a surfactant is added, followed by heating with stirring. When the temperature reaches 80-90 ° C., the crude pigment forms magma with β-naphthol. The mixture was further stirred at 95 ° C for 5 hours, cooled to 85 ° C,
Add 50 parts of a 2N aqueous sodium hydroxide solution to dissolve β-naphthol. The resulting pigment suspension was filtered by suction, washed with water until neutral, and dried to obtain 19.4 parts of a very bright and soft yellow pigment. Further, the alkali mother liquor after the separation of the pigment and the first washing liquid were cooled and acidified with hydrochloric acid to recover 38.3 parts of β-naphthol.

Example 8 32.8 parts of 2-nitro-4-chloroaniline were added to 200
Of 4N aqueous hydrochloric acid and dispersed at room temperature for 3 hours or more. After adding an additional 1.4 parts of anthranilic acid, the mixture is cooled to 0 ° C. with ice. Next, 48.3 parts of a 30% nitrous acid aqueous solution was added to diazotize the mixture. Excess nitrous acid was decomposed with sulfamic acid, diatomaceous earth was added, and insolubles were removed by filtration. A diazonium salt solution was obtained.

At the same time, add 46.6 parts of 5-acetoacetylaminobenzimidazolone together with an appropriate amount of a surfactant to 3
After dissolving in 05 parts of a 2N aqueous sodium hydroxide solution, the mixture was cooled and precipitated with 320 parts of a 2N aqueous acetic acid solution.
Adjust to ° C. The diazonium salt solution is added dropwise to the coupler suspension at 20 ° C. over 80 minutes, and the mixture is stirred for 2 hours or more to complete the coupling reaction. 41.5 parts of β-naphthol are added to the obtained suspension of the crude pigment, and the mixture is heated with stirring. As the temperature increases, the suspended crude pigment begins to agglomerate and at 80-90 ° C β
Form large magmas with naphthol. The mixture was further stirred at 95 ° C. for 3 hours and then cooled to 85 ° C.
Add 0 parts of a 2N aqueous sodium hydroxide solution to dissolve β-naphthol.

The resulting orange pigment suspension is filtered by suction,
After washing with water until neutral, it was dried to obtain 79.6 parts of a very bright and soft orange pigment. Also, the alkali mother liquor and the first washing liquid after separating the pigment are cooled,
By acidification with hydrochloric acid 39.5 parts of β-
Naphthol was recovered.

Example 9 106 parts (20 g of dry matter) of a crude pigment wet cake obtained in the same manner as in Example 1 were dispersed in 150 parts of water in the same manner as in Example 1, and then 18 parts of water was dispersed. β-naphthol and 2.5 parts of 1-naphthol-5-sulfonic acid were added, heated with stirring, and treated at 95 ° C. for 3 hours.
19.6 parts of a bright and soft orange pigment were thus obtained. 20 parts of β from alkaline mother liquor and washing solution
A mixture of -naphthol and 1-naphthol-5-sulfonic acid was recovered.

Comparative Example 7 A couple suspension of the crude pigment obtained in the same manner as in Example 4 was directly heated to 90 ° C., aged at 90 to 95 ° C. for 2 hours, and added with water. After cooling to 70 ° C., the mixture was subjected to suction filtration and water washing to obtain a yellow pigment wet cake 1
81 parts (dry matter 44%) were obtained.

45.5 parts of the above wet cake were added to 150 parts.
Of isopropanol and raise the temperature to 85 ° C. with stirring. Then, after aging under reflux for 5 hours, the temperature was lowered to 40 ° C. or lower, and filtration and washing were performed to obtain 18.6 parts of a greenish yellow pigment.

Comparative Example 8 45.5 parts of the crude pigment wet cake obtained in the same manner as in Comparative Example 7 was dispersed in 250 parts of water, and the temperature was increased to 130 ° C. while stirring. After aging for a period of time, the temperature was lowered to 80 ° C. or lower, and filtration and washing were performed to obtain 19.6 parts of a greenish yellow pigment.

Comparative Example 9 105 parts of a crude pigment wet cake obtained in the same manner as in Example 5 was dispersed in 200 parts by volume of dimethylformamide and aged for 3 hours under reflux. After cooling to 40 ° C., filtration and washing with methanol were dried to obtain 17.6 parts of a yellow pigment.

Comparative Example 10 The coupled pigment suspension obtained in Example 6 was heated to 90 ° C., aged at 90 to 95 ° C. for 2 hours, cooled to 70 ° C., and filtered and washed with water. As a result, 95 parts (dry matter: 35%) of a wet cake of a crude pigment was obtained. 57.1 parts of this wet cake was dispersed in 170 parts of water,
Add nitrobenzol and 1.6 parts sorbitan laurate and heat to 95 ° C. The mixture was boiled for 5 hours, cooled to 75 ° C., filtered and washed with water. After removing water as much as possible, nitrobenzol remaining in the pigment was further removed with methanol, and dried to obtain 18.6 parts of the pigment. Obtained.

Comparative Example 11 98.5 parts of a crude pigment wet cake obtained in the same manner as in Example 7 was dispersed in 200 parts by volume of water, and the yellow pigment 18.6 in the same manner as in Comparative Example 10. Got a part.

Comparative Example 12 The pigments obtained in Example 4 and Comparative Examples 7 to 8 were powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.).
Along with a commercially available pigment, Hoster Palm Yellow H3G (manufactured by Hoechst, equivalent to the pigment of Example 4 of the present invention, trademark), it was enameled with a melamine alkyd paint in the same manner as in Comparative Example 6, and the concentration, hiding power and The weather resistance was measured, and the results shown in Table 2 below were obtained.

(1) Density Dark enamel was prepared by mixing azo pigment: titanium white with 1:20.
After diluting with white enamel and spreading on art paper using an applicator (6 mils) and baking at 140 ° C. for 30 minutes, the coloring power was visually evaluated. Judgment is 1
The evaluation was performed in 0 stages (1 = poor → 10 = excellent). (2) Hiding power The dark enamel was spread on a hiding power test paper (manufactured by Nippon Test Panel Kogyo Co., Ltd.) using an applicator (6 mil), and baked at 140 ° C. for 30 minutes, and then visually observed. Judged. The judgment was made in five stages (1 = poor → 5 = excellent).

(3) Weather Resistance Dark enamel and light enamel diluted with white enamel so that the azo pigment: titanium white becomes 1:20 with a azo pigment: titanium white are adjusted to a viscosity suitable for spray coating with a solvent. And
Coating and baking were performed on a tin plate to obtain a colored coated plate. The colored coated plate was exposed to a sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.) for 500 hours, and the color difference ΔE from the unexposed coated plate was measured.

Table 2 (melamine alkyd baking paint test)

Comparative Example 13 The azo pigment obtained in Example 5 and Comparative Example 9 was powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.), and commercially available C.I.
I. P. Y. A color paste is prepared by kneading with DOP and 3-roll together with -120 (for example, PV First Yellow H2G, manufactured by Hoechst Co., Ltd., a pigment equivalent product of Example 5 of the present invention). Each color paste was kneaded with a vinyl chloride resin compound gelled at 160 ° C. on two rolls, and then kneaded at 170 ° C. at a temperature of 50 kg / cm ^2.
To create a comparative sheet with a load of
The light resistance and the migration resistance were measured, and the results are shown in Table 3 below.
I got the result. Judgment was made in five steps for each test item (1 = poor ← →
5 = Y).

Table 3 (Polyvinyl chloride test)

Comparative Example 14 The pigments obtained in Example 6 and Comparative Example 10 were powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.). I. P. Y. -151 (e.g., Hoster Palm Yellow H4G, manufactured by Hoechst, a pigment equivalent of Example 6 of the present invention, trademark), and enameled with a melamine alkyd paint in the same manner as in Comparative Example 6, to obtain a concentration, dispersibility, The opacity, weather resistance and sharpness were measured to obtain the results shown in Table 4 below. The judgment was made in five steps for each test item (1 = poor →→ 5 =
Yu).

Table 4 (Melamine alkyd baking paint test)

Comparative Example 15 The pigments obtained in Example 7 and Comparative Example 11 were powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.), and commercially available P
V First Yellow HG (manufactured by Hoechst Co., Ltd., a pigment equivalent of Example 7 of the present invention, trademark) was used to form an ink by the following method, and the density, dispersibility, and sharpness were measured, and the results shown in Table 5 below were obtained. Was.

(1) Preparation method of base ink Pigment: polyamide varnish: nitrified cotton varnish: 10% solvent
It is blended in a ratio of 58:17:15 parts. This was put into a mayonnaise bin together with 200 parts of steel balls, and dispersed for 40 minutes with a paint shaker to obtain a base ink. (2) Viscosity Using a rotational viscometer, 20 ° C., rotational speed 12 r.p. p. m. Was measured. (3) Concentration The base ink was diluted with white ink so that the azo pigment: titanium white became 1:20, spread on art paper using a # 6 bar coater, and the coloring power of the pigment of Comparative Example 15 was measured. It was judged visually with 100%.

(4) Dispersibility The dark enamel was measured with a grind gauge, and the dispersion particle size was determined. The judgment was made in five steps (1 = poor →→ 5 = excellent). (5) Sharpness The base ink was spread on art paper using a # 6 bar coater, and the sharpness was judged by comparison with the naked eye. The judgment was made according to [◎: large sharpness ~ 〇 ~ △ ~ ×: poor sharpness].

Table 5 (Gravure ink test)

Comparative Example 16 The pigments obtained in Examples 8 to 9 were powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.), and commercially available PV
It was made into an ink with the following method together with First Orange HL (manufactured by Hoechst, equivalent to the pigment of Example 9 of the present invention, trademark), and the transparency, concentration and fluidity were measured. The results shown in Table 6 below were obtained. .

(1) Preparation of Offset Ink 10 parts of an azo pigment and 90 parts of an offset ink varnish using a rosin-modified phenol resin as a binder were mixed to prepare an offset ink with three rolls. (2) Transparency Take a certain amount of the above offset ink, print it on black belt art paper with an RI tester (Meiji Seisakusho), and use a photoelectric colorimeter (manufactured by Suga Test Instruments Co., Ltd.) The L value was measured.

(3) Density The dark offset ink described above was diluted with white ink so that the azo pigment: titanium white became 1:20, spread on a spread paper using a spatula, and its coloring power was reduced. The determination was made visually with the pigment of Comparative Example 16 taken as 100%. (4) Fluidity A fixed amount of the offset ink prepared in (1) was measured with a spread meter measuring device (manufactured by Toyo Seiki Seisaku-sho, Ltd.), and the spread (mm) of the ink at 60 seconds was measured.

Table 6 (Offset ink test) Similar results were obtained by using α-naphthol or β-oxynaphthoic acid instead of β-naphthol in the above examples.

[Examples relating to naphthol-based pigment] Example 1 19.3 parts of n-butyl anthranilic acid ester was added to 20 parts.
0 parts of a 2N hydrochloric acid aqueous solution and stirred to dissolve.
Cool the temperature to 5 ° C. Then add 23.0 parts of 3
After diazotization by adding a 0% aqueous nitrous acid solution, excess nitrous acid was decomposed with sulfamic acid, and insolubles were removed with diatomaceous earth to obtain a clear colorless diazonium salt solution. Then, after mixing with a 2N aqueous sodium acetate solution, the temperature was adjusted to 10 to 15 ° C., and 34.0 parts of 5- (2 ′, 3′-
Oxynaphthoylamino) benzimidazolone to 130
Of a 2N aqueous solution of sodium hydroxide was added dropwise.

The pigment suspension obtained by this coupling reaction is heated to 90 ° C. and aged for 20 minutes to obtain a red crude pigment. Water is added to this crude pigment suspension and
After cooling to room temperature, suction filtration and washing with water were carried out to obtain 350 parts of a crude pigment wet cake (15.0% of dry matter).

After dispersing 175 parts of the above wet cake in 450 parts of water, 52.4 parts of β-naphthol are added and heated with stirring. At 80-90 ° C., a “flash” occurs, in which the crude pigment initially suspended in water migrates into the molten or molten β-naphthol and aggregates into small particles, which further aggregate to form a large red-brown magma To form The mixture was further stirred at 95 ° C. for 5 hours,
Cool to ℃ and add 250 parts of 2N aqueous sodium hydroxide solution to dissolve β-naphthol.

The resulting red pigment suspension was filtered by suction,
After washing to neutrality with water and drying, 26.2 parts of a very bright and soft red pigment were obtained. Also, from the alkaline mother liquor and the first washing liquid after the pigment was isolated,
After cooling, acidify with hydrochloric acid, precipitate and filter.
9.2 parts of β-naphthol were recovered.

Example 2 After dispersing 175 parts of the wet cake obtained in Example 1 in 450 parts of water, 13.1 parts of β-naphthol was added, heated with stirring, and stirred at 140 ° C. for 2 hours. After 8
Cool to 5 ° C. and add 120 parts of a 2N aqueous sodium hydroxide solution to dissolve β-naphthol.

The obtained red pigment suspension was filtered by suction,
After washing to neutrality with water and drying, 26.2 parts of a very bright and soft red pigment were obtained. After the pigment is isolated, the alkaline mother liquor and the first washing liquid are cooled, then acidified with hydrochloric acid, precipitated and filtered.
Three parts of β-naphthol were recovered.

Example 3 26.2 parts of β-naphthol was added to the coupling suspension of the red crude pigment obtained in the same manner as in Example 1, and the mixture was heated with stirring and kept at 140 ° C. for 2 hours. 85 after stirring
Cool to <RTIgt; C </ RTI> and add an aqueous solution containing 18 parts of caustic soda to dissolve <RTIgt; ss-naphthol </ RTI> and obtain a red pigment suspension.

The obtained pigment suspension was subjected to suction filtration, washed with warm water until neutral, and then dried to obtain 52.4 parts of a bright and soft red pigment. Further, from the alkaline mother liquor and the first washing liquid after the pigment was isolated, 24.0 parts of β-naphthol were recovered by cooling and then acidifying with hydrochloric acid.

Comparative Example 1 Next, for comparison with the pigment of the present invention, 175 parts (15% dry matter) of a crude pigment wet cake obtained by the same method as in Example 1 were used in the same manner as in Example 1. The mixture was dispersed in 450 parts of water, heated, and aged at 140 ° C. for 2 hours. After cooling to 85 ° C., filtration and washing with water were performed to obtain 26.2.
Parts of a red pigment were obtained.

Comparative Example 2 In the same manner as in Example 1, instead of β-naphthol, N,
140 ° C. using 13.1 parts of N-dimethylformamide
For 2 hours. After cooling to 85 ° C., the mixture was filtered and washed with water to obtain 26.2 parts of a red pigment.

Comparative Example 3 The red coarse pigment suspension obtained in the same manner as in Example 2 was directly aged at 140 ° C. for 2 hours. After cooling to 85 ° C., the mixture was filtered and washed with water to obtain 52.4 parts of a red pigment.

Comparative Example 4 The azo pigments obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.), and were rolled together with DOP by three rolls. Knead to create a color paste. Each color paste was kneaded with a gelled vinyl chloride resin compound at 160 ° C. on two rolls, and then a comparative sheet was prepared by applying a load of 50 kg / cm ² at a temperature of 170 ° C. to obtain a dispersibility and concealment. The light resistance and light resistance were measured.

The judgment was made in five stages for each test item (1 = poor →→).
5 = Y). Table 1 (Polyvinyl chloride test)

Example 4 11.5 parts of 1-amino-2-methoxy-5-methylbenzol-4-sulfonic acid methylamide were mixed with 75 parts of 2N
The mixture is added to an aqueous hydrochloric acid solution, and ice is added thereto while stirring, and the mixture is cooled to 0 ° C. Next, 11.6 parts of a 30% nitrous acid aqueous solution was added to diazotize the mixture. Excess nitrous acid was decomposed with sulfamic acid, and insoluble matter was removed by adding diatomaceous earth and filtration to obtain a clear diazonium salt. A solution was obtained.

At the same time, 17.0 parts of 5- (2 ′, 3′-oxynaphthoylamino) benzimidazolone are dissolved in 75 parts of a 2N aqueous solution of caustic soda to prepare a submerged solution. The diazo solution and the immersion solution were adjusted to the same volume, and while stirring vigorously, 200 parts of water and 50 parts of 2N
The solution is added dropwise to a buffer solution consisting of an aqueous acetic acid solution and 100 parts of a 2N aqueous sodium acetate solution over 30 minutes at room temperature, and further stirred for 1 hour or more to obtain a blue-red pigment suspension.

14 parts of β-naphthol are added to the obtained pigment suspension and heated with stirring. After aging at 140 ° C. for 2 hours, the mixture is cooled to 85 ° C. and an aqueous solution containing 9.5 parts of caustic soda is added to dissolve β-naphthol. The red pigment suspension was filtered by suction, washed with warm water until neutral, and then dried to obtain 28.0 parts of a very bright and soft blue-red pigment. After the pigment was isolated, the alkaline mother liquor and the first washing liquid were cooled and then acidified with hydrochloric acid to obtain 9.0 parts of β-acid.
-Naphthol was recovered.

Example 5 24.2 parts of 3-amino-4-methoxybenzoic anilide are added to 150 parts of a 2N aqueous hydrochloric acid solution and cooled to 0 ° C. Next, 24 parts of a 30% nitrous acid aqueous solution is added thereto to cause diazotization. The insoluble matter is added with diatomaceous earth, filtered, and then excess nitrous acid is decomposed with sulfamic acid. Further, 60 parts of a 2N aqueous acetic acid solution and 80 parts of a 2N aqueous sodium acetate solution are added thereto, and the mixture is sufficiently stirred to obtain a diazonium salt solution.

At the same time, 34 parts of 5- (2 ′, 3′-oxynaphthoylamino) benzimidazolone were dissolved in 150 parts of a 2N aqueous solution of caustic soda to prepare a solution for submersion. The solution is dripped while stirring. 28.6 parts of β-naphthol were added to the obtained coupling suspension, and 14
Heat at 0 ° C. for 2 hours. Then cool to 85 ° C,
An aqueous solution containing 9.8 parts of caustic soda is added to dissolve β-naphthol.

The resulting red pigment suspension was filtered by suction,
After washing to neutrality with water and drying, 57.1 parts of a very bright and soft red pigment were obtained. After cooling, 26.8 parts of β-naphthol were recovered from the alkaline mother liquor and the first washing with water after cooling and acidifying with hydrochloric acid.

Comparative Example 5 A couple suspension of the crude pigment obtained in the same manner as in Example 4 was directly heated at 140 ° C. for 2 hours, and then cooled to 70 ° C. by adding water. This red pigment suspension was subjected to suction filtration, sufficiently washed with water, and dried to obtain 28 parts of a red pigment.

Comparative Example 6 To a couple suspension of the crude pigment obtained in the same manner as in Example 4, 8.4 parts of N, N-dimethylformamide was added, and the temperature was raised to 140 ° C. while stirring. After aging for 2 hours, the temperature was lowered to 80 ° C. or lower, and suction filtration and washing were performed to obtain 28.0 parts of a bluish-red pigment.

Comparative Example 7 The azo pigments obtained in Example 4 and Comparative Examples 5 to 6 were powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.),
Together with three rolls to produce a color paste. 160 ° C for each color paste on two rolls
Then, after kneading with the gelled vinyl chloride resin compound, a comparative sheet was prepared by applying a load of 50 kg / cm ² at a temperature of 170 ° C., and the dispersibility, hiding property and light resistance were measured.

The judgment was made in five stages for each test item (1 = poor →→).
5 = Y). Table 2 (Polyvinyl chloride test)

Comparative Example 8 The pigments obtained in Example 4 and Comparative Examples 5 to 6 were used in Comparative Example 7
Powdered in the same manner as described above, and commercially available Nova Palm Carmine H
It was made into an ink with the following method together with F4C (manufactured by Hoechst, Inventive Example 4 pigment equivalent, trademark), and the viscosity, dispersibility and sharpness were measured to obtain the following results.

(1) Preparation of base ink: Pigment: nitrified cotton dope: solvent is mixed in a ratio of 10:10:15 parts. Put this in a mayonnaise bin
Add with 50 parts and disperse on a paint shaker for 40 minutes. A diluted varnish obtained by mixing a urethane varnish: solvent in a ratio of 30:35 parts was added thereto, and further dispersed for 5 minutes using a paint shaker to obtain a base ink.

(2) Viscosity The base ink was prepared by using a rotational viscometer at 20.degree.
r. p. m. Was measured. (3) Dispersibility The base ink was measured with a grind gauge, and the dispersion particle size was determined. The judgment was made in five steps (1 = poor →→ 5 = excellent).

(4) Sharpness The base ink was spread on a polyester film using a # 6 bar coater, and the sharpness was judged by comparison with the naked eye. Judgment [◎: Large sharpness ~ 〇 ~ △ ~ ×: Poor sharpness]
I went in.

Table 3 (Gravure ink test)

Comparative Example 9 A couple suspension of a crude pigment obtained in the same manner as in Example 5 was directly heated at 140 ° C. for 2 hours, and then cooled to 70 ° C. by adding water. The red pigment suspension was subjected to suction filtration, washed sufficiently with water, and dried to obtain a red pigment.
One part was obtained.

Comparative Example 10 The azo pigments obtained in Example 5 and Comparative Example 8 were powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.), and kneaded with DOP with three rolls to form a color paste. I do.
After kneading each color paste into a gelled vinyl chloride resin compound at 160 ° C. on two rolls,
A comparative sheet was prepared at a temperature of 0 ° C. while applying a load of 50 kg / cm ² , and the dispersibility, hiding property and light resistance were measured.

The judgment was made in five stages for each test item (1 = poor →→).
5 = Y). Table 4 (Polyvinyl chloride test)

Example 6 17.0 parts of 2,5-dichloroaniline was added to 100 parts of warm water, and heated and melted on a hot plate.
Next, 100 parts of a warm 4N hydrochloric acid aqueous solution was added thereto, and heating was continued to dissolve the oil droplets. Then, the mixture was cooled to 0 ° C. or less with ice, and 24.5 parts of a 30% aqueous sodium nitrite solution was added. Perform diazotization. Excess nitrous acid was decomposed with sulfamic acid, and insolubles were removed with diatomaceous earth to obtain a clear colorless diazonium salt solution.

Next, the mixture was mixed with 125 parts of a 2N aqueous sodium acetate solution and, if necessary, added with an emulsifier, and then the temperature was adjusted to 5 to 10 ° C. to give 31.9 parts of 5- (2 ′, 3′-).
Oxynaphthoylamino) benzimidazolone to 145
Of a 2N aqueous solution of caustic soda was added dropwise,
Stir for an additional hour to complete the coupling.

37.5 parts of β-naphthol are added to the coupling suspension of the black crude pigment, and the mixture is heated with stirring. The suspension is further stirred at 140 ° C. for 2 hours, cooled to 85 ° C., and β-naphthol is dissolved by adding an aqueous solution containing 20 parts of caustic soda to obtain a black-brown pigment suspension.

The obtained pigment suspension was subjected to suction filtration, washed with warm water until neutral, and then dried to obtain 48.5 parts of a soft black-brown pigment. Further, from the alkaline mother liquor and the first washing liquid after the pigment was isolated, 36.2 parts of β-naphthol were recovered by cooling and then acidifying with hydrochloric acid.

Example 7 A coupling suspension of a black crude pigment obtained in the same manner as in Example 6 was directly heated to 90 ° C., and further aged at this temperature for 1 hour to obtain a blackish crude product. Get the pigment. After adding water to the crude pigment suspension and cooling to 70 ° C., suction filtration and washing with water were carried out to obtain a wet pigment 365 of the crude pigment.
(Dry matter 13.4%).

After dispersing 187 parts of the above wet cake in 450 parts of water, 25.0 parts of β-naphthol are added and heated with stirring. The suspension is further stirred at 140 ° C. for 2 hours and then cooled to 85 ° C., and β-naphthol is dissolved by adding 120 parts of a 2N aqueous sodium hydroxide solution.

The resulting blackish brown pigment suspension was filtered by suction, washed with warm water until neutral, and dried to obtain 24.2 parts of a soft blackish brown pigment. Also, from the alkaline mother liquor and the first washing liquid after the pigment was isolated,
After cooling, acidify with hydrochloric acid, precipitate and filter.
4.3 parts of β-naphthol were recovered.

Comparative Example 11 Next, for comparison with the pigment of the present invention, 187 parts (13.4% dry matter) of a crude pigment wet cake obtained in the same manner as in Example 7 were used. 450 in a similar way
After dispersing in water, the mixture was heated and aged at 140 ° C. for 2 hours. After cooling to 85 ° C., filtration and washing with water were performed.
6 parts of a dark brown pigment are obtained.

Comparative Example 12 187 parts (13.4% of dry matter) of a crude pigment wet cake obtained in the same manner as in Example 7 was mixed with 108 parts of N,
After being dispersed in N-dimethylformamide, the mixture was heated and aged at 140 ° C. for 2 hours. After cooling to 85 ° C., filtration and washing were performed to obtain 19.8 parts of a black-brown pigment.

Comparative Example 13 The black coarse pigment suspension obtained in the same manner as in Example 6 was directly aged at 140 ° C. for 2 hours. After cooling to 85 ° C., the mixture was filtered and washed with water to obtain 49.0 parts of a black-brown pigment.

Comparative Example 14 The azo pigments obtained in Examples 6 to 7 and Comparative Examples 11 to 14 were
Powdered using a sample mill (manufactured by Kyoritsu Riko Co., Ltd.)
Commercially available C.I. I. P. Br. -25 (for example, Hoster Palm Brown HFR, manufactured by Hoechst Co., Ltd., a pigment equivalent product of Example 6 of the present invention, trademark) and enamelled with a melamine alkyd paint, and dispersed particle size, viscosity, color tone, hiding power and weather resistance are obtained by the following methods. The properties were measured and the results shown below were obtained.

(1) Method of preparing enamel Pigment: varnish: solvent was mixed in a ratio of 10: 170: 20 and dispersed in a ball mill for 12 hours to prepare a dark enamel. (2) Viscosity Using a rotational viscometer, 20 ° C., rotation speed 12 r.
p. m. And the TI value (η ₆ / η ₆₀ ) were measured.

(3) Density Dark enamel was prepared by mixing azo pigment: titanium white with 1:20.
After diluting with white enamel and spreading on art paper using an applicator (6 mils) and baking at 140 ° C. for 30 minutes, the coloring power was visually evaluated. Judgment is 1
The evaluation was performed in 0 stages (1 = poor → 10 = excellent).

(4) Dispersibility The dark-colored enamel was measured with a grind gauge, and the dispersion particle size was determined. The judgment was made in five steps (1 = poor →→ 5 = excellent). (5) Weather resistance Dark enamel and dark enamel were diluted with white enamel so that the ratio of azo pigment: titanium white was 1:20, and light enamel was adjusted to a viscosity suitable for spray coating with a solvent. Coating and baking were performed thereon to obtain a colored coated plate. The colored coated plate was exposed for 600 hours with a sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.), and the color difference ΔE from the unexposed coated plate was measured.

Table 5 (Melamin alkyd baking paint test)

[0129]

According to the present invention, a crude azo pigment is heat-treated with hydroxynaphthalene or a derivative thereof at a temperature of 80 ° C. or higher, generally at normal pressure, to convert the crude pigment into a paint or gravure ink. Crystals can be grown to a form suitable for use.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tamaki Shibata 1-7-6 Nihombashi Bakurocho, Chuo-ku, Tokyo Inside Dainichi Seika Kogyo Co., Ltd. (72) Inventor Hiroshi Tsuchiya 1-7 Nihonbashi Bakurocho, Chuo-ku, Tokyo No. 6 Inside of Dainichi Seika Kogyo Co., Ltd. 5-9400 (JP, A) JP-B-45-14425 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09B 67/20 C09B 67/10 CAPLUS (STN) REGISTRY (STN ) WPIDS (STN)

Claims (5)

(57) [Claims] Claims 1. A crude azo pigment is converted into an aqueous suspension with an aromatic compound having a water-soluble group at a temperature of 80 ° C or higher for a sufficient time to convert crystals of the crude pigment into a pigment form. The aromatic compound having a water-soluble group is dissolved in water with an alkaline aqueous solution, the method for producing an azo pigment for separating the pigment-form product ,
Crude azo pigments have benzimidazolone groups in the structure
In the case of an acetoacetic anilide-based azo pigment, the acid of the pigment is used.
Aqueous or neutral aqueous suspensions and crude azo pigments
Azo pigments having a benzimidazolone group on the surface
In the case of the above, a neutral aqueous suspension of the pigment
In the process of raising the temperature to the temperature, the pigment in the aqueous phase is
To form magma by transferring to the aromatic compound phase
Thereafter, the temperature is further increased, and the magma is subjected to a heat treatment at the above temperature . 2. A water-soluble crude azo pigment as an aqueous suspension.
At a temperature of 80 ° C. or higher together with an aromatic compound having a functional group.
Heat treatment for a reasonable time to transform the crude pigment crystals into pigment form
After conversion, the aromatic compound having the water-soluble group
Is dissolved in water with an alkaline aqueous solution, and the face
In a method for producing an azo pigment for separating a charge product,
Crude azo pigments have benzimidazolone groups in the structure
Aniline acetoacetate and naphthol azo pigments
And heating an alkaline aqueous suspension of the pigment at the above temperature.
A method for producing an azo pigment, which comprises treating. 3. A water-soluble crude azo pigment as an aqueous suspension.
At a temperature of 80 ° C. or higher together with an aromatic compound having a functional group.
Heat treatment for a reasonable time to transform the crude pigment crystals into pigment form
After conversion, the aromatic compound having the water-soluble group
Is dissolved in water with an alkaline aqueous solution, and the face
In a method for producing an azo pigment for separating a charge product,
Naphtho having a crude azo pigment having a benzimidazolone group
Azo pigments, and pressurize a neutral aqueous suspension of the pigment.
Heat treatment at a temperature of 100 ° C. or more below
For producing azo pigments. 4. The method according to claim 1, wherein the aromatic compound having a water-soluble group is hydroxynaphthalene or a derivative thereof. 5. hydroxynaphthalene or derivatives thereof, alpha-naphthol, beta-naphthol, alpha-naphthol or beta-naphthol halide, sulfonated, carboxylated product or method according to claim 4 which is a mixture thereof .